COMPARISON OF GLASS-TRANSITION TEMPERATURES FOR EPOXY POLYMERS OBTAINED BY METHODS OF THERMAL ANALYSIS

In this review, the characteristic temperatures for epoxy polymers and epoxy matrices of fiber-reinforced composites in the glass-transition (alpha-transition) range determined using different methods of thermal analysis (DSC, DMA, and TMA) are compared. The influence of loading frequency in the DMA method and of uniformity of heating and postcuring of specimens in all the methods is revealed. The agreement between the glass-transition temperatures given by different methods is achieved using the same characteristic points in experimental curves and the same time parameters (the frequency of external actions, heating rate, and the uniformity of temperature distribution in specimens in testing chambers).